This project will make available to the social science, public health, and other research communities a Super Sample of data from the 1990 U.S. Census long form file. The file will comprise 15.9% of households and persons in the U.S. The National Institute for Child Health and Human Development has contracted with the Bureau of the Census to have the file created. In Phase I, Public Data Queries, Inc., will: (1) provide access to the NICHD 1990 Super Sample to a wide audience of users; (2) make value-added improvements to the Super Sample data and documentation; (3) incorporate expert and intelligent tools in the PDQ-Explore interface to facilitate use of the Super Sample data; (4) begin to investigate the feasibility and practicality of extending the tabulation/description/extraction capabilities into a full statistical system. The project encompasses two primary tasks. The first is to make more than fifty million housing and person-level microdata records interactively accessible to researchers and other users through the PDQ- Explore information system. The second is to identify the types of user support that might be provided through expert systems and intelligent agents and to investigate the feasibility of implementing these tools with PDQ-Explore. PROPOSED COMMERCIAL APPLICATION: Distribution of census data is a marketable service. Addition of the 1990 Super Sample to the PDQ-Explore data base along with enhanced documentation, an expert system, and linkage to a statistical software system with dramatically improve access to the 1990 Super Sample and the information within it and other census long form files that may become available. The added features will also increase the marketability of PDQ-Explore.